Underreamer.



- To all whom it may concern.'

UNTED STATES PATENT OFFICE..

ELIHU c. WILSON, or Los Y UN DEBBEAMBE.

Bp'ecieation of Letters Patent. l Patented play 16, 1916.

A Applicationiled Iax'ch 18, 1913.l vSerial No. 755,170.

Be it known that I Enum C. WILSON, a citizen of the United States, residing at Los' Angeles, in the -county of Los Angeles and State of California, have invented new and useful Improvements in Underreamers, of which the'following is a specification.

This invention relates to underreamers, such as are employed in enlarging oil well and other well holes lto permitthe lowering of the casing in the holev following the drilling operation; and the invention constitutes an improvement upon,- or de arture from the invention disclosed in an patentedby Letters Patent of the United States issued to me July 31, 1906, for L underreamers, Number 827,595. Y .The present invention relates particularly to the .means for holding one end of the, spring which is employed in expanding the cutters or bits ofthe reamerinto working position. It has been found in practice that the means disclosed in said Letters Patent Number 827,595, while operative and performing the functions required of them, are, under certain conditions, open to certain objections which are overcome by the use and substitution therefor of the meansset forth and embodying the present invention.

' The present invention has for particular objects the provision of an improved underreamer, and particularly of improved means of the general nature specified as a feature of underreamers, which will be superior in point of simplicity and inexpensiveness of construction, facility in assembling and disconnection of )arts and features,durability or length of life. freedom from liability to get out of order in long continued service, and positiveness in operation, and which will be generally superior in eliciency and serviceability.

lVith the above and other objects in view the invention consists in the novel and useful provision, formation, construction, combination. association and relative arrangement oi parts. members and features, all as hereinafter described. shown in the, drawing andgiinally pointed out in claims.

In the drawing: Figure 1 is a fragmentary vertical sectional view of a portionof a joint of casing such as is employed in well holes with the shoe thereof. and further of the principal .features of construction of an improved underreamer constructed and organized in accordance with the invention, the cutters or bits being in contracted positions; Fig. Q is a similar view showing the cutters in expanded positions; Fig. 3 is a fragmentary view of the. underreamer with the cutters or bits removed, the view being taken in a line of vision at right .angles to that of Figs. 1 and 2; and Fig. 4 is a detail transverse sectional viewtaken upon the line *-a:, Fig. 1, and looking in the direction of the appended arrows.

Qorresponding parts in all the figures are` designated by the same reference characters.

. Referring with particularity to the draw- .-ing, 5 designates the hollow body and A and B the cutters or bits of an underreamer constructed to embody the invention in one form `,The underreamer is shown as within the casing (i and the shoe 7 in Fig. 1, and as projected at its lower end beneath the shoe in Fig. 2, the cutters being held collapsed in F ig. 1, by the shoe and casing, and being in expanded positions in Fig. 2, such expansion being caused by a coil spring 8 within the hollow body 5 and surrounding a rod or mandrel 9, which plays vertically in the hollow body, the spring being confined between a nut or removable stop 10 at the upper end of the spring actuated rod or mandrel 9, and a key 11 detachably accommodated within a transverse slot l2 in the rod 9 adjacent to the lower end thereof. The slot 12 is elongated longitudinally of the rod, so that the key may reinain in relatively fixed position during the longitudinal movement of the rod. A transverse slot 13 in the hollow body 5 permits the insertion and withdrawal of the key. The key 11 is provided with tapered end portions 11?, and with a bottom extension or head 11b which fits withinthe bore of the hollow body being held therein by the tension of the spring 8, and etfectually preventing the key from displacement. The transverse slot 13 in the body isof width,

as is the slot 12, properly to snuglyfaccomll'eilgcs are employed for both vided with slots, a key mounted in said slots, said key having a projection or wing projectin downward from thc slot of the body into t e central bore and preventin lateral motion of the ke a spring mounte( on said key and coiled a out said rod, means at the upper end of said rod adjustably connecting said rod and spring, means at the lower end of said rod for enaging and supporting the bits or cutters, an cutters or bits.

6. An underreanier comprising a body having a central bore, a rod or mandrel mounted in said bore, said body provided with a slot, said rod provided with a longitudinal slot, a key or 'b mounted in said slot and provided with a ownwardly projecting portion adapted to contact with the wall of the central bore below said slot and prevent lateral displacement of the key from either side of the slot, a spring mounted on said gib and operatively connected with said rod, said rod provided at its lower end with a bit engaging head or key.

7. An underreamer comprising a body having a central bore, a spring actuated rod mounted in said bore, said rod provided with bit carryin means, and a key loosely mounted in said ody and held therein by the ten'- sion of said spring.

8. An underreamer comprising a hollow body, a sprin actuated rod mounted therein and provide with bit carryin means, and a key loosely mounted in saidA od and operatively connecting said rod and ody.

9. An underreamer comprising a hollow body, a reciprocating rod, a spring and a key operatively mountin said rod in said body, said key fitting loose y in said body and held therein by spring tension on the top, and means preventing the key -sliding laterally in the ody without overcoming the downward pressure of the spring on the key.

10. An underreamer comprising a body having a central bore, a rod or mandrel mounted in said bore, said body and rod provided with registering slots, a key or b mounted in said slots, the slot in the rod ing of suiiicient longitudinal extension to permit the movement of said rod longitudinally of said body, a key or gib loosely mounted in said slots and havin a projection or wing projecting downwar into the central bore elow the walls of the slot in the body and anchoring said key or gib against movement transversely of said body, a spring mounted on said gib and operatively connected with said rod, said rod provided at its lower end with bit engagin means, bits tiltingly carried thereby, and earings for the inner faces of said bits formed on said rod and ada ted to prevent lateral displacement of said its. In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

' ELIHU C. WILSON. Witnesses:

RAYMOND J. BLAxEsLmi, ALFRED H. DAEHLER. 

